She sounds like she's too warm. She doesn't really need the heating pad, they're typically used for older or sick hedgies that need the extra warmth. I would take it away and see if she goes back to sleeping in her bed. For sleeping, that's typical. Babies sleep a LOT, so that's perfectly normal for her to be sleeping most of the time. Sometimes they do nothing but sleep, eat, and poop - just like human babies.
Most hedgies are a tad grumpy upon being woken up, just like humans can be. What time are you getting her up? If it's during the day, that may be part of her grumpiness. If you're doing it in the evening/night to get her out for bonding time, don't worry about it. Keep doing it, around the same time every day if you can, and she'll get used to the schedule and come to expect you. Keep in mind that she may also be going through quilling right now, which will make her grumpier too.
For litter training, don't expect too much of her. Babies poop a lot and often will go everywhere. They also have less control over their bowel movements and may just go wherever they happen to be at the moment. She may catch on eventually and use her litterbox, she may never use it. Some are just messy and don't care where they go. Is the box underneath the wheel? That might help as well, since most hedgehogs potty on their wheel, even if they're litter-trained.
Just be patient with her and give her time. She's still learning everything right now, getting used to her new home, and quilling. All of that is overwhelming for a little one.